Systems for non-invasive treatment of skin disorders known in the art. Typically, such system includes a cabinet into which a laser is placed and an articulated arm connected a handpiece that conducts the laser radiation from the laser to a segment of skin to be treated. The functionality of such a system is limited by the capabilities of the selected laser. Treatment of skin imperfections usually requires more than one type of laser and frequently more than one type of laser is placed in the cabinet. This increases size, cost and complexity of the system.
Treatment of some skin imperfections requires significant laser power (tens and even hundreds of MW) that in order to prevent skin damage is supplied in ultrashort femto or picosecond pulses. Such laser power is difficult to transfer through a fiber and use of articulated arm significantly limits the freedom of the caregiver.
Microchip lasers are alignment-free monolithic solid-state lasers where the active laser media is in direct contact with the end mirrors forming the laser resonator. In many cases the mirrors, which are dielectric coatings, are simply deposited on the end faces of the active laser media. Microchip lasers are usually pumped with a laser diode and typically emit on average a few tens or hundreds milliwatts of power, although reports of microchip lasers emitting 10 W have been published. The dimensions of the microchip laser are small and support their placement in almost any desired place in the system.
A typical Q-switched microchip lasers consist of a laser medium and a saturable absorber as a passive Q-switcher bonded together as one element. Microchip lasers are small, linear cavity, monolithic solid-state lasers with dielectrically coated cavity mirrors. The typical cavity length is on the order of millimeter. The short cavity lengths result in extremely short cavity lifetimes, and the possibility of much shorter Q-switched pulses. It has been demonstrated that Q-switched microchip lasers can produce output pulses shorter than 300 ps, as short as large mode-locked lasers produce with peak powers of about 10 KW, similar to commercially available large Q-switched systems produce.
Over decades, a lot of effort has been put in places striving for generation of high energy picosecond lasers. Many techniques have been developed. These techniques commonly involve multi-stage configurations, i.e., a low energy picosecond seed laser, for example nJ or μJ are fed into amplification stages (including regenerative amplifier or/and multi-pass amplifications). Such multi-stage configurations require complex optical arrangement and sophisticated electronic synchronization further increasing the complexity and cost of the system.[16, 17, 18, 20, 25, 28]